On March 28, 1979, 35 years ago this year, America’s worst nuclear power disaster occurred when Unit 2 of the Three-Mile Island nuclear reactor experienced a partial meltdown. Although little radiation was released, the disaster, which prompted the evacuation of pregnant women and pre-school age children from a 5-mile radius around the plant, eroded the public’s faith in nuclear power. Tighter government regulations coupled with anti-nuclear safety concerns effectively ended U.S. nuclear reactor construction.

2. Exxon Valdez Oil Spill

Prince William Sound, Alaska

One of the America’s worst environmental disasters occurred March 24, 1989, when the Exxon Valdez oil tanker struck Bligh Reef in Prince William Sound Alaska. In the days that followed, more than 10 million gallons of crude oil poured into the Pacific Ocean, eventually covering more than 11,000 square miles of water and polluting 1,300 miles of shoreline. Salmon, sea otters, seals, seabirds and other sea life, communities and industries along the coast suffered. The remote location of the spill made clean up efforts especially challenging. After 25 years, groups such as the Exxon Valdez Oil Spill Trustee Council are still working to repair the damage created by the disaster. Congress passed the Oil Pollution Act of 1990 among other new laws tightening regulations for oil tankers and advancing preparedness for future disasters.

3. Texas City Disaster

Texas City, Texas

On April 16, 1947, the ammonium nitrate-laden SS Grandcamp exploded at the dock in Texas City, Texas. The explosion destroyed the town’s fire department, which had been battling a blaze in the ship’s cargo hold and killed hundreds of spectators that had gathered along the dock. After the first explosion, the fire spread to a nearby Monsanto chemical plant and a major oil pipeline, which allowed fires to spread throughout the now-defenseless city. Later in the night, another ship exploded. The town was decimated. 576 confirmed deaths. Thousands were injured and hundreds of homes and buildings were destroyed. The incident prompted legislative action by Congress for better disaster preparedness as well as tighter control on the transportation of dangerous chemicals. Many lawsuits followed from the people affected by the events.

4. Kansas City Hotel Walkway Collapse

Kansas City, Missouri

On July 17, 1981, more than 1,000 people were dancing and socializing at the Hyatt Regency Hotel in downtown Kansas City when a skywalk on the fourth floor collapsed, bringing other steel, concrete, and glass structures down too. The debris crashed onto the event-goers in the concourse below, killing 114 people. Engineers who designed the skywalks were stripped of their licenses, but not charged with criminal negligence.

5. American Airlines Flight 191 Crash

Chicago, Illinois

Often cited as the worst single plane disaster in U.S. history, American Airlines Flight 191 crashed shortly after takeoff from Chicago O’Hare International Airport on May 25, 1979. The plane, carrying 258 passengers and 13 crewmembers, went down when the left engine broke away from the plane. The McDonnell Douglas DC-10 crashed in an open field killing everyone on board plus two on the ground. An FFA inspection found that the engine detached due to faulty ground maintenance and not the design of the aircraft itself.

6. Peshtigo Fire

Peshtigo, Wisconsin

The Peshtigo Fire, which started October 8, 1871, as a controlled burn to clear forested land for future building spread due to winds from fast-moving cold front. The massive blaze grew into a firestorm that razed 12 communities. Over 1,200 were confirmed dead and hundreds more considered missing. The devastating Peshtigo Fire is largely overshadowed by another fire that occurred on the same day — the Great Chicago Fire. Later, during World War II, research conducted after the Peshtigo Fire was used in firebombing campaigns against Japan and Germany.

7. Indiana State Fairgrounds Coliseum Explosion

Indianapolis, Indiana

During a performance of “Holiday on Ice,” on Halloween 1963, a propane tank leaked gas into the concession area of the Indiana State Fairgrounds Coliseum. The gas, ignited by an electric popcorn machine, caused an explosion that killed 74 people and injured hundreds more. Another tragedy occurred at the same venue during the Indiana State Fair in August 2011. Winds from an incoming storm caused an outdoor state to collapse, 7 people died and 58 were injured. Both incidents triggered investigations and studies to prevent future accidents.

8. I-35 Mississippi River Bridge Collapse

Minneapolis, Minnesota

The eight-lane bridge carrying Interstate 35 over the Mississippi River collapsed on August 1, 2007, during rush-hour traffic in Minneapolis. The bridge was one of the busiest bridges in the city. When it collapsed, approximately 100 vehicles were involved, including a school bus carrying 64 children on a field trip. Thirteen were killed and 145 injured. An official investigation into the disaster revealed a flaw in design of the 40-year-old bridge was responsible for the collapse. A new bridge, the I-35 Saint Anthony Falls Bridge, was built and opened on September 18, 2008. Since the disaster individual states around the country have increased bridge safety to prevent events like this from happening again.

9. Johnstown Flood

South Fork, Pennsylvania

Built in the mid 19th century, the South Fork Dam was built as part of a canal system on Lake Conemaugh near South Fork, Pennsylvania. On May 31, 1889, due to extremely heavy rain, the dam failed and released over 20 million tons of water into the communities below. The water, which was equal to the force of the Mississippi River, decimated surrounding communities, killing 2,209 people including 99 entire families. This disaster was the first that the American Red Cross, led by Clara Barton, was able to assist with, marking a significant moment in the history of disaster preparedness and response efforts. The Johnstown Flood and South Fork Dam failure resulted in many lawsuits, ultimately leading to the decision that non-negligent landowners could be held responsible for damages caused by various uses of private land.